Can opener



H. GARRISON Dec. 4, 1928.

CAN OPENER Filed April 50, 1928 cameos,- or carcass, armors;

' can OPENER. 7

-- awicetibn 'nieanpm to, 1amissuer-imam are.

i he'otsiea of this i i'ivention is, to effect a certain improvement inthe commonest type of can opener, which is characterized by a terminalguiding fulcrum and a downwardly offset uppercut blade extending farenoug past the stock to permit of penetration.

Commercial openersof this type have a cutting edge of about one inch inlength, no

practical way of inserting and operating a longer knife having beenWorked out. I employ a cutting edge of one andone-half inches. I

An attempt to use a knife of this length develops a number ofdifficulties. Some of F these are solved by previous applications onwhich patents have been granted, and solutions of others will bereserved for future applications. p i

Fig. 1 exhibits a side view of the opener, showing the stock A fittedinto a handle, and knife, comprising blade B and shank C, the latterbeing riveted to the stock. Cutting edges are indicated by double lines,the lower being required for the introduction of the lengthened knifeinto the can.

Fig. 2 is a fragmentary top plan view, showing the end of the'stock Abent aside to form the fulcrum member D. The blade is.

curved to fit a round can, and the widening of its vertical projectionis due to a vertical curve in the blade.

Fig. 3 is'a View of the anterior face of the fulcrum member, showing thenotch E which forms the guiding fulcrum.

Fig. 4 represents in alternative constructions, at and y, a verticalsection of the blade on the line.44 of Fig. 1 looking-in-thedirection ofthe arrow.

Figs. 5, 6, 7 8, and 9 will be used in explaining the operation, of theinstrument with relation .to the vertical curvature exhibited in Fig. 4,which forms the basis of the claim which is sought by this application.

The difliculties encountered in operating the lengthened knife withwhich this application is concerned, and which are met by eitherconstruction of Fig. 4, are two in number, and will be considered inorder.

When an opener of this type is to be inserted, the blade is thrustvertically downward until the end of the stock strikes the top of thecan, as illustrated by a diagram,Fig. 5'.

Insertion is completed by composition of two motions, whose directionsare indicated by the arrows. With the lengthened knife, the

principal ofthesemotions isthat indicated 7 the upper arrow, which iseffected by prying the knife backward into the can. For this reason theback of the knife is sharpened.

A long initial gash will be made in the can, which may be almostthelengt-h of the knife, equivalent to half a dozenkerfs made by theshort blades now in use. 7

Fig. 6 shows by a dotted line K F an incision of sufficient length topermit the can to be opened. The double line K H indicates the initialgash above referred to, which is made by the lower cutting edge;

Fig. 7 shows part of a can in axial section, and a vertical section ofan uncurved blade in the process of descending into the can by means. ofits lower cutting edge, somewhere.

on the line K H. The displaced rim of tin at the edge of the severedportion of the top of the can is bent down to form the burr Z. This burris troublesome. After the knife has been inserted in theinitial-incision K H, and we attempt to move it forward, itis liable tostick fast in the incision. This is occasion-ed both by the burr, whichwill catch onto the upper cutting edge, and by the narrowness of thelong incision, through which the shank can not be moved with sufficientease and celerity.

To remove this obstacle to operation, I, widen the incision K H, andthis result is attained by making the blade concavo-convex in verticalsection, as shown in Fig. 4. This vertical curving may embrace the wholewidth of the blade, as shown by w, or only a part of it, as in 3 Thesecond difliculty to be considered in this application, and which is metby the same construction, is occasioned wholly by the burr Z. This willextend along the inner side of the curve K H, and has the effect ofreinforcl on 4 K H'remains in position and the tin bends on I the line FH, thus losing the advantage of the initial incision K H. q

Fig. 8 shows the vertically curved blade of :22, Fig. 4, descending. Itwill make a clean cut on the side toward the center of the can,

the displaced tin being pushed down by the convex side of the blade, inthe position shown by Fig. 9.

This construction applied to the rearward its shank to said stock, itsblade extendin part of the blade will prevent the formation forward pastthe guidingfulcrum; said knil e of the burr on the inner ed e oftheincision having acuttin fedge' on its lower margin adjacent the point K,so that the loosened and being lateral y curved in the direction 0:

6 part of the top of the can Willbend back on its length and the blade,in a region posterior V the-line F K. V t to the fulcrum, beinglaterally curved in the I claim:

direction of its vertical width, presenting in 7 A can opener in theform of a leverof the vertical section a curve which is concave on lsecond class, having a guiding fulcrum that side which faces the centerof curvature l 10 formed at the end of a handled stock, and a of thedirectional curve of the knife.

downwardly ofiset uppercut knife secured by j HERMAN GARRISON.

